TWI546124B - Process for making improved catalysts from clay-derived zeolites - Google Patents

Description

Method for producing improved catalyst from zeolite derived from clay

This invention relates to a process for the manufacture of a zeolite-containing catalyst derived from a clay treated with a source of cerium oxide under alkaline conditions. This method is particularly directed to the manufacture of a catalyst suitable for use in a fluid catalytic cracking process.

Catalytic cracking is a petroleum refining process for very large-scale commercial applications. Most refined petroleum products are produced using a fluid catalytic cracking (FCC) process. The FCC process essentially involves cracking a heavy hydrocarbon feedstock into a lighter product by contacting the feedstock in the recycle catalyst recycle cracking process with a circulating fluidizable catalytic cracking catalyst inventory, the catalyst stock being averaged. The particles are comprised of particles between about 20 microns and about 150 microns, preferably between about 50 microns and about 100 microns.

When a relatively high molecular weight hydrocarbon feedstock is converted to a lighter product by catalytic cracking at elevated temperatures in the presence of a catalyst, most of the conversion or cracking occurs in the gas phase. The feedstock is converted to gasoline, distillate, and other liquid cracking products as well as lighter gas cracking products having four or fewer carbon atoms per molecule. This gas portion is composed of olefins and partly composed of saturated hydrocarbons. Bottom and coke are also produced.

The cleavage catalyst is generally composed of several components, each of which is used to enhance the overall performance of the catalyst. FCC catalysts are generally composed of zeolites, active matrices, clays, and binders, and combine all the ingredients into a single particle.

The zeolite component is primarily used to convert (eg, crack) hydrocarbons. Zeolite components suitable for this purpose include a wide variety of zeolites. Suitable large pore zeolites include crystalline yttrium aluminate zeolites such as synthetic faujasite, i.e., Y zeolite, zeolite X and zeolite beta, and heat treated (calcined) derivatives thereof. Frequently used zeolites include the ultra-stable Y-type zeolite (USY) as disclosed in U.S. Patent No. 3,293,192.

Zeolites derived from specific clays are also known. See U.S. Patent No. 3,459,680. Such a zeolite can be prepared into a crystalline form by treating the clay powder with a ceria source under alkaline conditions (referring to the caustic substance in the '680 patent), and combining the obtained zeolite with the matrix precursor to form a suitable one. Catalyst in the conversion process. Preformed clay-containing microparticles, such as spray-dried microspheres, can also be processed to the size and form suitable for such methods, and the zeolite can be generated in situ within the microparticles. See U.S. Patents 4,493,902 and 6,656,347. In either method, the resulting zeolite contains metallic impurities such as iron, magnesium, calcium and titanium which are typically present in the clay used to make these zeolites. Such impurities tend to destabilize the yttrium oxide alumina zeolite structure, thereby causing collapse of the structure. This will result in a loss of zeolite surface area and thus a loss of catalytic activity in the hydrocarbon conversion process. Furthermore, zeolites made from clay tend to have a smaller crystal size and thus have lower hydrothermal stability than zeolites made from synthetic starting materials.

Summary of invention

When the zeolite derived from clay is a component containing a zeolite catalyst, it has been found that the addition of cerium to clay-derived zeolite improves the maintenance of the surface area of the zeolite.

Invention methods based on this discovery include:

(a) treating the clay with a source of cerium oxide under alkaline conditions to produce zeolite, and

(b) The zeolite is combined with a ruthenium compound, wherein the lanthanide is measured as yttrium oxide (Y ₂ O ₃ ) in an amount of from 0.5% by weight to 15% by weight based on the weight of the zeolite.

The invention is particularly suitable for the manufacture of zeolites from kaolin or kaolin clay (e.g., metakaolin, spinel and/or mullite) that have been calcined into one or more characteristic phase transitions. Alkali metal hydroxides, citrates or aluminates are suitable reagents suitable for use in producing the basic conditions of the present invention. Sodium citrate, colloidal cerium oxide, precipitated cerium oxide, tannin extract and rice husk ash are all suitable sources of cerium oxide. The combination of clay and ceria source, optionally including seed crystals, accelerates the crystallization of the zeolite, especially under alkaline conditions.

The invention is particularly suitable for zeolites prepared from clays containing metal impurities, such as compounds derived from iron, magnesium, calcium and titanium, which may be present in the zeolite after zeolite formation.

The amount of strontium fossils combined with the zeolite is from 0.5 to 15% by weight based on the weight of the zeolite, wherein the lanthanide is measured by its oxide Y ₂ O ₃ . The cerium compound preferably contains no more than 50% by weight of the rare earth oxide, and the weight of the rare earth oxide is based on the sum of the cerium oxide plus the rare earth oxide. Therefore, a suitable ruthenium compound contains a rare earth oxide in a weight ratio of 0.01 to 1 with respect to the lanthanum oxide.

A ruthenium compound consisting essentially of a ruthenium compound or moiety is a particularly suitable embodiment.

The ruthenium compound selected from the group consisting of ruthenium halide, ruthenium nitrate and ruthenium sulfate is a compound particularly suitable for the present invention.

The zeolite and ruthenium compounds can then be further processed to produce a catalyst. In one embodiment of the invention, the zeolite produced from the clay comprises crystalline particles having a particle size in the range of from 0.01 to 10 microns. Accordingly, the present invention also encompasses the incorporation of a combination of zeolite and cerium with a precursor of a matrix which is typically formed when the catalyst is formed (e.g., by spray drying).

In another embodiment of the invention, the clay is a microparticle, such as a dried microsphere, having an average particle size in the range of 20 to 150 microns, and the zeolite is produced in situ within the clay microparticle. The clay particles are treated with a source of cerium oxide under alkaline conditions. This form of zeolite is combined with a ruthenium compound by impregnation or ion exchange of ruthenium into zeolite-containing microparticles. Impregnation or ion exchange with an aqueous solution containing a cesium salt concentration of from 1 to 40% by weight is particularly suitable for use in such embodiments. The zeolite particles are then further processed, for example dried, after it has been combined with the hydrazine compound in (b). Upon further processing to produce a catalyst, the zeolite particles can also be calcined and further exchanged with the ammonium salt to reduce the sodium content of the zeolite particles.

These and other aspects of the invention are described in more detail below.

Detailed description of the invention

It has been found through research that the addition of cerium to clay derived from clay can result in the maintenance of the surface area of the zeolite when subjected to conditions in the FCC process.

It is often accompanied by lanthanum and lanthanide metals in rare earth minerals, occasionally known as rare earth metals. However, niobium itself is not considered to be a rare earth metal. The atomic order of the element 钇 is 39, and therefore does not have a family of rare earth elements having an atomic order of 57 to 71 in the periodic table. Metals having an atomic order within this range include ruthenium (atomic sequence 57) and lanthanide metals. See Hawley's Condensed Chemical Dictionary, 11th Edition (1987). Therefore, the term "rare earth" or "rare earth oxide" as used hereinafter means a lanthanum and a lanthanide metal, or a corresponding oxide thereof.

As used herein, the term "antimony compound" refers not only to hydrazines (e.g., sulfonium salts) which are present in the formula, but also to the cations of the cations, such as phosphonium cations exchanged on zeolites. Unless otherwise mentioned, the words "钇 compounds" and "乙" will be used interchangeably. Unless otherwise indicated herein, the weight measurement of the ruthenium or osmium compound is carried out by elemental analysis techniques conventionally used in the art and is described in the form of yttrium oxide (Y ₂ O ₃ ). Analytical techniques include, but are not limited to, inductively coupled plasma (ICP) analysis.

For the purposes of the present invention, the term "zeolite surface area" as used herein refers to the surface area of zeolite or micropores of less than 20 angstroms in square meters per gram. See, Johnson, MFL, Journal of Catalysis , Vol. 52, (1978), pp. 425-431.

The invention preferably forms a catalyst that can be maintained within the FCC unit. The FCC catalyst usually contains a zeolite which is a fine porous powder material composed of an oxide of cerium and aluminum. Zeolites are typically incorporated into the matrix and/or binder and micronized. See "Commercial Preparation and Characterization of FCC Catalysts", Fluid Catalytic Cracking: Science and Technology, Studies in Surface Science and Catalysis, Vol. 76, p. 120 (1993). When the above zeolite particles are introduced into the gas, the particulate catalytic material will reach a fluid-like state, so that the material behaves like a liquid. This property allows the catalyst to be in better contact with the hydrocarbon feedstock fed to the FCC unit and can be cycled between the FCC reactor and other units of the entire FCC unit, such as the regenerator. Therefore, the industry uses the word "fluid" to describe this material. FCC catalysts typically have an average particle size in the range of from about 20 to about 150 microns. However, the compositions produced by the present invention have been shown to be particularly suitable for use in FCC, and it is contemplated that the compositions made in accordance with the present invention may also be used in other catalytic hydrocarbon conversion processes using clay-based zeolite catalysts. Among them, it is desirable to maintain the zeolite surface area of the catalyst and the activity of the catalyst.

Zeolite

As described above, the zeolite used in the present invention is produced by treating clay with a ceria source under alkaline conditions. Processes for the manufacture of such zeolites are known and described in U.S. Patent No. 3,459,680, the disclosure of which is incorporated herein by reference. Other methods of making zeolites from clay are also disclosed in U.S. Patent Nos. 4,493,902 and 6,656,347, the disclosures of each of each of each These methods will be described in more detail below.

Montmorillonite and kaolin clays are suitable for use in the present invention. Kaolin is preferred. Other clays such as those described in the '680 patent are also suitable. The clay word in this article refers not only to the clay material that exists in its original form at the time of mining, but also to the green clay that has been calcined into one or more characteristic transformations. See Brindley et al., "The Kaolinite-Mullite Reaction Series", Journal of the American Ceramic Society , Vol. 42, Vol. 7, (1959), p. 311; Duncan et al., "Kinetics and Mechanism of High- Temperature Reactions of Kaolinite Minerals", Journal of the American Ceramic Society , Vol. 52, vol. 2, (1969), p. 74 et al. For example, calcining kaolin clay in a temperature range of about 480 to about 985 ° C, converting kaolin into metakaolin; calcining at a temperature of up to about 985 to 1100 ° C, converting kaolin or metakaolin into a tip Spinel; and calcination at temperatures above 1100 ° C to convert the kaolin and/or kaolin properties into meta-rich mullite.

The treatment of clay can be suitably carried out by contacting the selected clay with a source of ceria (such as tannin, colloidal ceria, precipitated ceria, rice hull ash, sodium citrate and/or mixtures thereof). Performing, wherein the clay and the ceria source are contacted or treated under alkaline conditions to crystallize the zeolite, followed by ion exchange to remove sodium and selectively incorporated metal cations in one or more steps, and The calcination is carried out at a temperature ranging from about 350 to about 850 ° C to superstabilize the zeolite. The calcined material can then be further processed. When the catalyst is prepared in accordance with the '680 patent, it is particularly suitable to grind the particle size of the calcined material to a range of from 7 to 10 microns. In this embodiment, the zeolite will combine with the ruthenium compound and the matrix precursor to form microparticles suitable for use in the FCC. The fine particles produced in this manner usually have an average particle diameter in the range of 20 to 150 μm.

The seed crystal is selectively combined with the ceria source and clay. The seed crystal is also known as the initiator of the zeolite. Briefly, seed crystals are used to initiate the crystallization of the zeolite from the above components, and may include (and herein define "seed" as) any material containing cerium oxide and aluminum oxide which may render the zeolite The crystallization process does not occur without the presence of this initiator, or it significantly shortens the crystallization process in the absence of it. Typical seeds have an average particle size of less than 1 micron and the seed is analyzed by X-ray diffraction and may or may not exhibit crystallographically detectable properties. Such seed crystals are known in the art and can be derived from a variety of sources, such as powders recovered from previous crystallization methods, or sodium citrate solutions. See U.S. Patent 4,493,902.

The zeolite prepared in this manner may have a pore structure having an opening in the range of 4 to 15 angstroms, but preferably having a pore size of at least 7 angstroms.

Alternatively, the zeolite is produced from particulate clay which has been formed to be suitable for use in a hydrocarbon conversion process, for example having an average particle size in the range of from 20 to 150 microns. Next, the clay particles are contacted with the ceria source under alkaline conditions to form zeolite on and in the surface of the particles. This embodiment is also related here to the in situ formation of zeolite within the clay particles. A more detailed discussion of the preparation of clay-derived zeolites and their catalysts is provided below.

One example is the use of a zeolite prepared in accordance with U.S. Patent No. 4,493,902, the disclosure of which is incorporated herein by reference. Please refer to the method disclosed in column 8 of the '902 patent. In short, kaolin clay can be calcined through its characteristic transition phase to produce phase change products at the specified calcination temperature. In one embodiment, the clay is calcined at a temperature ranging from about 985 to 1100 ° C to produce a spinel (but not an aluminum-rich sulphate), or the kaolin can be calcined at a temperature above 1100 ° C. Aluminum-rich red column soil. The calcined product from any of the calcining processes can be ground or further processed to facilitate bonding with additional clay. For example, one or both types of calcined clay can be combined with kaolin for further processing, for example, combining kaolin and its calcined product in an aqueous slurry and spray drying the clay to an average particle size. Particles in the range of 20 to 150 microns. These particles are formed using conventional spray drying techniques.

The formed microparticles are then calcined at a temperature ranging from about 480 to about 985 °C. Calcination converts kaolin into metakaolin, thus producing a microparticle comprising metakaolin and a phase change of spinel and/or aluminum-rich sorghum kaolin added to the original slurry (either one or both) ). Therefore, calcined granules suitable for use in the present invention include those containing 20 to 60% by weight of metakaolin and 40-75% of which are calcined into one or more characteristic transformation phases, such as spinel-containing, red-rich red columns. Calcined product of soil and / or a mixture thereof.

Other embodiments of the invention include forming individual kaolin particles and individual calcined kaolin particles, mixing the individual particles, and then calcining the mixture to form 20 to 60% by weight of metakaolin and 40 to 75 % A composition of calcined clay containing spinel, aluminum-rich red pillar soil or a mixture thereof.

The formation of zeolites from clay particles can be accomplished by treating the clay particles with a ceria source under alkaline conditions, optionally including the seed crystals described above. This treatment is generally carried out in an aqueous slurry. Such treatment typically involves heating the particulate and ceria source to a temperature for a period of time to produce particles comprising zeolite (e.g., zeolite Y) in an amount of at least 30%, and typically from 50 to 70% by weight. Within the range of zeolites. The heating temperature may be in the range of 82 to 110 ° C, and the heating is carried out for 10 to 120 hours.

Another embodiment includes the use of clay particles prepared in accordance with U.S. Patent No. 6,656,347, the disclosure of which is incorporated herein by reference. Briefly, the clay is processed into zeolite-containing particles comprising a macroporous matrix and the crystallized zeolite coats the inner walls of the matrix pores.

Zeolites prepared in accordance with the present invention can be (typically) further processed to enhance the functional performance of the zeolite as a catalyst. Further processing includes rinsing the zeolite and/or removing impurities, such as sodium compounds or "sodium bases", which are produced by the formation of zeolites. Processing involves the exchange of zeolites to remove sodium using conventional techniques. The exchange can occur before or after the particles are combined with the ruthenium compound. Zeolites are generally exchanged with rare earths. If the exchange is carried out after the addition of hydrazine, it is expected that this exchange will become such that the exchange of any hydrazine is miniaturized to maximize the maintenance advantage of the zeolite surface area.

Accordingly, the present invention may comprise zeolite processing, so that the sodium content of the zeolite is reduced to Na ₂ O between 0.1% to 14% by weight. Further processing also includes the above-described ion exchange, and calcination in a temperature range of 100 to 750 ° C for subsequent processing (exchange) so that the Na ₂ O content of the catalyst is lowered to the aforementioned level. Conventional methods using ammonium (e.g., ammonium nitrate) are suitable for ion exchange.

Further processing of the zeolite in the manner described above can also be carried out after the zeolite has been combined with the cerium compound, for example, after the addition of cerium to the zeolite, in particular via exchange. In examples of such embodiments, after the yttrium exchanged zeolite, Na ₂ O in an amount of from about 4 wt% of an oxide. In a typical example embodiment, may then be processed by the yttrium exchanged zeolite ion-exchanged, so that the number of Na ₂ O is reduced to 1.0 wt% of Na ₂ O.

Zeolites prepared from clay typically have a metal impurity content in the range of from 0.2 to 3% by weight based on the weight of the zeolite. These impurities are naturally found in the starting clay and eventually become residual impurities in the zeolite product. These impurities include various forms of metal species and compounds, and typically include compounds derived from metals such as iron, titanium, magnesium, calcium, and mixtures of two or more thereof. In general, the metal impurities comprise oxides of iron oxide and/or magnesium, calcium, potassium and titanium. See U.S. Patent No. 5,891,326. It is believed that these metallic impurities destabilize the yttrium aluminum oxide structure of the zeolite, thereby causing a loss of zeolite surface area, which in turn is converted to a lower conversion activity in cracking hydrocarbons. The method of the invention is directed to the treatment of such problems, particularly for metallic impurities that are difficult to remove.

yttrium

The amount of rhenium added to the process of the invention is between about 0.5 and about 15 weight percent of the weight of the zeolite bound to the rhodium, which is measured as Y ₂ O ₃ .

Zeolite prior to combination with the yttrium compound, and typically will be rinsed and dried, if it is a system which is desired to reduce the content of Na ₂ O before addition of yttrium compound is determined. In fact, the method of the present invention generally comprises a system after the zeolite are processed (e.g., switching and rinsed to remove Na ₂ O), yttrium compound is added to the zeolite. However, it is also possible to add a ruthenium compound to the zeolite before reducing the Na ₂ O content. The ruthenium compound can also be added before, during or after the addition of optional ingredients such as rare earths.

The amount of oxide added to the final catalyst can also be measured by the amount of oxide form, in grams per square meter of catalyst surface area. For example, the foregoing cerium content can be at least about 5 micrograms per square meter of total catalyst surface area. The more commonly found tantalum is at least about 20 micrograms per square meter of total catalyst surface area. The weight and surface area are measured by ICP and BET surface area methods, respectively.

In one embodiment of the invention, the combination of ruthenium and zeolite allows the ruthenium to be exchanged directly on the zeolite prior to the addition of any optional ingredients. This embodiment can be carried out in an aqueous exchange bath containing a soluble onium salt. Suitable soluble salts include cerium halides (e.g., chlorides, bromides, fluorides, and iodides), nitrates, sulfates, acetates, carbonates, bromates, and iodates. The water-soluble salts of this embodiment, such as the above-listed water-soluble salts other than carbonates, are characterized herein as being soluble in acid and added in the form of an aqueous solution having a cerium concentration of 1 Up to about 40% by weight, and possibly containing one or more rare earths, having a weight ratio of 0.01 to 1 with respect to Y ₂ O ₃ , but a preferred weight ratio is not more than 0.5. Preferably, the cerium compound consists essentially of a cerium compound or a cerium-containing moiety, and the content of any rare earth is minimal, and the amount contained in the final catalyst does not exceed 5% by weight of the zeolite. Solutions of the above salts may also be used in several embodiments of the invention, including adding cerium to the zeolite along with any of the optional ingredients described below, or adding cerium to the zeolite-containing particles, The microparticles are prepared by alkaline treatment of a clay particle that has been processed into a form suitable for use in FCC.

The cerium compound may also be impregnated onto the zeolite by conventional methods, or on the zeolite-containing microparticles, for example, an aqueous solution of the cerium compound may be added to the zeolite until the initial wetting is reached, and then the impregnated zeolite or microparticles are dried.

Although not a typical or preferred method, an antimony compound such as cerium oxide or cerium hydroxide can be used in the present invention. Compounds such as cerium oxide and/or cerium hydroxide are insoluble in water but soluble in acidic environments such as acidic binders. In order to exchange the ruthenium into the zeolite, ruthenium hydroxide and ruthenium oxide may be added to the clay-derived zeolite in the presence of such a binder.

It is generally desirable that the ruthenium be located within the pores of the zeolite. When the lanthanide is added via the pre-exchange method described above, most of the added ruthenium will be located in the pores of the zeolite. However, it is also possible that some of the defects will be located in the pores of the catalyst matrix. When the embodiment of the invention is used and in which the lanthanide is added to the zeolite in the slurry of zeolite, matrix precursor and/or other optional ingredients and the slurry is processed to form the final catalyst material, it is often found in the catalyst matrix. The existence of 钇. When zeolites generated in situ in clay microparticles are used, it is also found in such an embodiment that rhodium appears in the pores of the catalyst matrix. In these embodiments, the amount of ruthenium in the matrix can be as high as about 25% of the amount of ruthenium contained in the composition.

Matrix and binder precursor

Still other ingredients may be combined with the zeolite and the cerium compound, including but not limited to precursors for the matrix and/or binder. These additional ingredients will be suitable, and in particular embodiments, such as the use of zeolites prepared from clay having a particle size between 0.01 and 10 microns, it will be desirable to have the catalyst suitable for use in FCC. Accordingly, the present invention still further includes the formation of catalyst particles from zeolite, ruthenium and a matrix and/or binder precursor. Such precursors can also be used in the practice examples using zeolites derived from clay particles having an average particle size in the range of 20 to 150 microns. For example, the precursor can be added before the clay is micronized. In fact, if the clay particles formed by U.S. Patent No. 6,656,347 are used, an alumina-rich precursor may be a suitable choice. These ingredients are referred to as precursors because they can be further processed and/or converted via the presence of zeolite and ruthenium compounds to form a matrix or binder for the final catalyst containing zeolite and ruthenium.

Suitable matrix precursor materials include, but are not limited to, active substrates such as alumina, ceria, porous yttrium aluminum oxide and kaolin clay. For some embodiments of the invention, alumina is a preferred choice and may form all or part of the active matrix component of the catalyst. The term "active" refers to the activity of the material in converting and/or cracking hydrocarbons in a typical FCC process.

It is also suitable for the production of catalysts, especially peptized alumina for the manufacture of FCC catalysts. See, for example, U.S. Patent Nos. 7,208,446, 7,160,830 and 7,033,487. The peptized alumina referred to herein specifically refers to those which are solubilized with acid and may also be referred to as "acid peptized alumina". Acid peptized alumina is prepared from alumina which is capable of being peptized and includes those aluminas which are known in the art to have a high peptizing index. See, for example, U.S. Patent No. 4,086,187; or the peptable alumina described in U.S. Patent No. 4,206,085. Suitable aluminas include the aluminas described in U.S. Patent No. 4,086,187, at col. 6, line 57 to column 7, line 53, the disclosure of which is incorporated herein by reference.

Suitable precursors for binders include those which bind the matrix and zeolite to the particles. Specific suitable binders include, but are not limited to, alumina sol, cerium oxide sol, aluminum oxide, and yttrium aluminum oxide.

Other ingredients

Addition and choice of components other than the binder precursor matrix may be those conventionally gasoline to reduce emissions from the regenerator exhaust gas (e.g., NO _x and SO _x), in order to reduce fractionation products prepared by the FCC naphtha of sulfur The component added to the FCC catalyst, such as the content. The ZSM-5 containing additives and/or products used to enhance the olefins in the FCC process are also well suited as optional ingredients.

Method of manufacturing catalyst

The method of the present invention comprises combining clay-derived zeolites and cerium (selectively in combination with a matrix and/or binder precursor), as well as other optional ingredients as described above. Such clay-derived zeolites are made by treating the clay in the manner previously described, and this method includes, but is not necessarily limited to, the following specific methods.

(1) ion-exchange or impregnation of a clay-derived zeolite with a ruthenium compound, followed by combining the ion-exchanged or impregnated zeolite with a matrix and/or binder precursor and any other previously mentioned optional ingredients, and forming a catalyst for manufacture The combination.

(2) Combining clay-derived zeolites, hydrazine compounds, matrix and/or binder precursors, and any other optional ingredients, either simultaneously or in any order, and forming a combination of catalysts required for production.

(3) Forming a clay-containing particle having a size and form suitable for fluidization, and treating the particles with a source of ceria (selectively seeding) under alkaline conditions to form a zeolite The ruthenium compound present in the form of an exchange medium or bath is either combined via impregnation. The resulting particulate material can then be further dried to produce the desired catalyst.

As previously mentioned, spray drying is one of the processes that can be used in any of the above methods that will combine to form microparticles which will ultimately become the desired catalyst. Spray drying conditions are well known in the art. For example, after the cerium exchanged zeolite of (1) or the zeolite and cerium compound of (2) is combined with the precursor of the matrix and any optional components in water, the resulting slurry can be spray dried into particles (for example, microspheres). It has an average particle size in the range of from about 20 to about 150 microns. Spray drying can also be used to prepare the clay particles of the method (3). The inlet temperature of the spray dryer is between 220 ° C and about 540 ° C, however the outlet temperature is between 130 ° C and 180 ° C.

As previously stated, the ruthenium compound in any of the above methods is generally in the form of a phosphonium salt and includes, but is not limited to, ruthenium halides such as chlorides, bromides and iodides. Sulfate, nitrate and acetate are also suitable sources. The source of hydrazine is preferably water based and the hydrazine is present at a concentration of from about 1 to about 40%. If the lanthanide is exchanged with the zeolite prior to addition to the substrate and/or binder precursor and any other optional ingredients, it is generally preferred that at least 15% up to about 90% of the exchange sites on the zeolite are exchanged by the ruthenium cation.

If the cerium compound is from a rare earth mineral, rare earth salts of cerium and/or lanthanides may also be present in the cerium compound and/or cerium exchange bath. Suitable rhodium compounds contain rare earth oxides in a weight ratio of from 0.01 to 1 relative to the cerium oxide. Preferably, the ruthenium compound consists essentially of a ruthenium compound or a ruthenium-containing moiety, and the content of any rare earth is minimal, and the amount contained in the catalyst is preferably not more than 5% by weight based on the weight of the zeolite.

Where the matrix and binder are included in the optional ingredients, these materials are added to the mixture of zeolite and hydrazine compound in the form of dispersions, solids and/or solutions. Suitable matrix and binder precursors are generally those previously described. The kaolin clay matrix precursor is particularly suitable, and particularly suitable binder materials include aluminum hydroxychloride or Ludox from WR Grace & Co.-Conn. A cerium oxide sol such as colloidal cerium oxide.

Once the catalyst is formed, conventional techniques can be used to further process the catalyst. For example, the catalyst may optionally be rinsed to remove excess alkali metal (e.g. Na ₂ O), which is known for the catalyst contaminants, in particular FCC catalyst. The catalyst can be rinsed one or more times, preferably with water, ammonium hydroxide and/or an aqueous ammonium salt solution such as ammonium sulfate, ammonium chloride or ammonium nitrate. The rinsed catalyst is separated from the rinse slurry by conventional techniques (e.g., filtration) and dried to reduce the moisture content of the particles to the desired extent, typically at temperatures ranging from about 100 °C to 300 °C.

The dried catalyst can then be used directly as a finished catalyst or calcined for activation prior to use. The catalyst particles can be calcined at a temperature ranging, for example, from about 250 ° C to about 800 ° C for from about 10 seconds to about 4 hours. The catalyst particles are preferably calcined in a temperature range of from about 350 ° C to about 600 ° C for about 10 seconds to 2 hours.

The present invention produces a catalyst that can be used as a catalytic component of a circulating catalyst inventory in a catalytic cracking process, such as the FCC process. For convenience, the present invention relates to the FCC process, although the catalyst of the present invention can also be used in a moving bed (TCC) cracking process as long as the particle size is appropriately adjusted to meet the requirements of the process. In addition to adding the inventive catalyst to the catalyst inventory and some possible changes in the product recovery section, as discussed below, the FCC method does not operate substantially differently.

However, the invention is particularly suitable for use in an FCC process in which a hydrocarbon feedstock will be cracked into a lighter product which is a feedstock and recycled fluid catalytic cracking catalyst inventory in a recycle catalyst recycle cracking process. In contact, the catalyst inventory is comprised of particles having an average particle size between about 20 microns and about 150 microns. The important steps of the cyclic process are: (i) catalytic cracking of the catalytic cracking zone (generally the riser cracking zone) in which the feed is operated under catalytic cracking conditions, by means of a feed and heat regeneration cracking catalyst Source contact to produce an effluent comprising a cracking product and a spent catalyst comprising coke and a strippable hydrocarbon; (ii) discharging the effluent and (generally in one or more cyclones) separated into a vapor phase rich in the cracking product and a solid phase rich in the catalyst; (iii) taking the vapor phase as a product, and fractionating in the FCC main column and its accompanying secondary column to form a Gas and liquid cracking products of gasoline; (iv) stripping used catalyst, usually in steam, to remove trapped hydrocarbons from the catalyst, followed by oxidative regeneration of the stripped catalyst To generate a hot regenerative catalyst, which is then recycled to the cracking zone for cracking a greater amount of feed.

A typical FCC process is carried out at a reaction temperature of from about 480 ° C to about 570 ° C, preferably from about 520 ° C to about 550 ° C. The temperature of the regeneration zone will vary with the particular FCC unit. As will be understood by those skilled in the art, the catalyst regeneration zone can be comprised of a single or multiple reaction vessels. The regeneration zone temperature is generally in the range of from about 650 ° C to about 760 ° C, preferably from about 700 ° C to about 730 ° C.

The stripping zone may suitably be maintained at a temperature in the range of from about 470 ° C to about 560 ° C, preferably from about 510 ° C to about 540 ° C.

Catalysts prepared from clay-derived zeolites are sometimes used in FCC processes conducted under the conditions described above. Such catalysts, like catalysts made with other matrices, are often added to the circulating FCC catalyst inventory during the cracking process, or they may be present in the inventory at the start of the FCC operation. As will be appreciated by those skilled in the art, these catalyst particles can also be added directly to the lysis zone, the regeneration zone of the FCC cleavage apparatus, or any other suitable location in the FCC process.

The invention is particularly useful when clay is used to make zeolites, particularly those containing metallic impurities. The following examples demonstrate that clay-derived zeolites are inherently less stable than zeolites synthesized from higher purity reagents such as sodium citrate and sodium aluminate. This instability is attributed to the small crystal size of metallic impurities and clay-based zeolites. Surprisingly, it has been found that when clay-based zeolites are exchanged by hydrazine, their stability disadvantages relative to zeolites synthesized from higher purity reagents are removed. When hydrazine is a component of a catalyst containing such a clay-based zeolite, especially when it is used as a substitute component of rare earth (a regular component in FCC catalyst), it is used. After deactivation by standard deactivation criteria for assessing catalyst activity and properties, the catalyst exhibits high zeolite surface area maintenance and activity. The results of the following examples show that catalysts prepared with other types of zeolites do not achieve the same effect. Accordingly, the present invention is believed to produce a clay-derived zeolite catalyst having particularly more stable activity.

When the present invention is added to an FCC unit, other catalytically active components may be present in the inventory of the recycled catalyst material in addition to the cracking catalysts prepared by the present invention and/or included in the present invention. Examples of such other materials include octane boosting catalysts based on ZSM-5 zeolite, CO combustion promoters based on supported precious metals (such as platinum), flue gas desulfurization additives such as DESOX (magnesium aluminum spinel), vanadium trapping agent, bottoms cracking additive, for example in Krishna, Sadeghbeigi (supra) and Scherzer, "Octane Enhancing Zeolitic FCC Catalyst", Marcel Dekker, NY, 1990, ISBN 0-8247-8399- 9, pp. 165-178, and the gasoline sulfur reduction product as described in U.S. Patent No. 6,635,169. These other ingredients can be used in their conventional quantities.

It is within the scope of the invention to use the cracking catalyst composition of the present invention alone or in combination with other conventional FCC catalysts, including, for example, zeolite catalysts having a faujasite cracking component. , for example, Venuto and Habib, as described in the Basic Review of Fluid Catalytic Cracking with Zeolite Catalysts , Marcel Dekker, New York 1979, ISBN 0-8247-6870-1, and in many other sources, such as Sadeghbeigi, Fluid Catalytic Cracking Handbook , Houston's Gulf Publishing Company, 1995, ISBN 0-88415-290-1. The FCC catalyst is usually composed of a binder (usually cerium oxide, aluminum oxide or yttrium aluminum oxide), an active component of the Y-type zeolite acidic site, one or more matrix alumina and/or yttrium aluminum oxide, and clay (such as kaolin clay). Composition. The Y-type zeolite in such a catalyst may be present in one or more forms and may be ultra-stabilized and/or treated with a stabilizing cation such as any rare earth.

The following specific examples are presented to further illustrate the invention and its advantages. The examples provided are specific illustrations of the invention. However, it should be understood that the invention is not limited to the specific details of the embodiments.

All parts and percentages referred to in these examples, as well as in the remainder of this patent application, relating to solid compositions or concentrations are by weight unless otherwise indicated. However, unless otherwise stated, all parts and percentages of the gas compositions referred to in these examples, as well as the remainder of this patent application, are based on moles or volumes.

In addition, any numerical range recited in the specification or the scope of the claims, such as the specific combination of the properties, the unit of measurement, the condition, the physical state, or the percentage, is meant to be explicitly recited herein by reference, or included in Reference is made to a subset of any number in any range, any number falling within the range.

Example

The zeolite derived from clay was prepared in the following manner and was then used in the following examples.

3712 grams of seed crystals, 17671 grams of sodium citrate, 14862 grams of water, and 250 grams of sodium hydroxide were mixed to produce a 7.7 SiO ₂ :Al ₂ O ₃ :2.3 Na ₂ O:100 H ₂ O The molar ratio of the reaction mixture. As soon as the sodium hydroxide was dissolved, 3,550 g of metakaolin clay was added with stirring, and the mixture was maintained at 99 ° C for one hour with stirring. The reaction mixture was then aged for five days in an oven set at 100 °C. After five days, the zeolite product was filtered and rinsed with water, rinsed with 40 kg of 10% ammonium sulfate solution, and rinsed with water.

The zeolite product will be further processed to remove sodium from the zeolite. The zeolite was first calcined at 621 ° C (1150 ° F) for 1 hour, followed by re-slurrying and stirring in an ammonium sulfate bath. The weight ratio of zeolite, ammonium sulfate and deionized water is 1:1:10. The product was filtered and re-slurryed again in an ammonium sulfate bath of lower ammonium sulfate concentration (1:0.25:10 by weight of zeolite, ammonium sulfate and deionized water). The product was then rinsed, rinsed again, and subjected to elemental analysis. The results are reported in column 2 of Table 1 below.

A reference USY zeolite was also selected for use in the following examples. This zeolite has been used as a commercial catalyst and is prepared using materials other than clay. The elemental analysis of this zeolite is presented in column 1 of Table 1.

The compositions of the ruthenium solution and the ruthenium solution used in the following examples contained the elements listed in Table 2 below. These solutions are aqueous solutions, and the RE ₂ O ₃ system represents the total content of lanthanum and lanthanide metals, and if they are present, the lanthanum and lanthanide metals are listed separately in the following RE ₂ O ₃ projects. Each of the following elements is described in the form of an oxide.

Example 1. Catalyst 1 was produced from a hydrazine solution and the above-referenced USY zeolite. Add 5856 g (dry basis is 1558 g) with reference to USY, 3478 g (dry basis is 800 g) aluminum hydroxychloride, 947 g (dry basis 500 g) alumina, 2471 g (dry basis 2100 g) clay. And 370 g (100 g of dry basis) aqueous solution of hydrazine solution, and mixed for about 10 minutes. The mixture was ground in a Drais mill to reduce particle size and spray dried in a Bowen spray dryer with an inlet temperature of 343 °C. The spray dryer had a feed solids content of about 38% by weight. The spray dried particles were calcined at 593 ° C for 1 hour.

In addition to the above-described clay-derived zeolite to replace the USY zeolite, a second catalyst was prepared in a manner similar to the preparation of the catalyst 1. Add 2431 g (1281 g dry basis) clay-derived zeolite, 2365 g (dry basis 544 g) aluminum hydroxychloride, 982 g (dry basis 340 g) alumina, 1440 g (dry basis 1224 g) clay And 252 g (dry basis is 68 g) aqueous solution of hydrazine solution, and mixed for about 10 minutes. The mixture was ground in a Drais mill to reduce particle size and spray dried in a Bowen spray dryer with an inlet temperature of 343 °C. The spray dryer has a feed solids content of about 40% by weight. The spray dried particles were calcined at 593 ° C for 1 hour. The second catalyst is hereinafter referred to as Catalyst 2.

Example 2. Catalyst 3 was produced from a hydrazine solution and the reference USY zeolite used in Example 1. Add 5856 g (dry basis is 1558 g) with reference to USY, 3478 g (dry basis is 800 g) aluminum hydroxychloride, 947 g (dry basis 500 g) alumina, 2471 g (dry basis 2100 g) clay. And 307 g (70 g dry basis) of an aqueous solution of hydrazine solution, and mixed for about 10 minutes. The mixture was ground in a Drais mill to reduce particle size and spray dried in a Bowen spray dryer with an inlet temperature of 343 °C. The spray dryer had a feed solids content of about 38% by weight. The spray dried particles were calcined at 593 ° C for 1 hour.

Catalyst 4 was prepared in a manner similar to the preparation of Catalyst 3, except that the clay derived zeolite was used in place of the USY zeolite. Add 2431 g (1281 g dry basis) clay-derived zeolite, 2365 g (dry basis 544 g) aluminum hydroxychloride, 982 g (dry basis 340 g) alumina, 1440 g (dry basis 1224 g) clay And an aqueous solution of 219 g (48 g dry basis) of hydrazine solution and mixed for about 10 minutes. The mixture was ground in a Drais mill to reduce particle size and spray dried in a Bowen spray dryer with an inlet temperature of 343 °C. The spray dryer has a feed solids content of about 40% by weight. The spray dried particles were calcined at 593 ° C for 1 hour. The fourth catalyst is hereinafter referred to as catalyst 4.

Example 3. The physical and chemical properties of the catalysts 1, 2, 3 and 4 (fresh samples) are listed in Table 3 below.

As can be seen from Table 3, the catalyst 4 produced from clay-derived zeolite and YCl ₃ has similar wear resistance (DI) and higher ABD (compared to the catalyst 2 made of clay-derived zeolite and LaCl ₃ ). Average bulk density) and similar surface area. To determine the Davison attrition index (DI) of the present invention, 7.0 cubic centimeters of sample catalyst was screened to remove particles in the range of 0 to 20 microns. The remaining particles are then contacted in a hard steel spray cup with a precision drilled hole through which a 21 liter/minute humidified (60%) air jet is passed through for 1 hour. DI is defined as the percentage of 0-20 micron fines produced during testing relative to the amount of material present > 20 microns, which is shown below.

DI = 100x (% by weight of 0-20 micron material formed during the test) / (weight of material 20 microns or more before testing)

Deactivation of all four catalysts was then performed using deactivation criteria CPS (metal free) and surface area measurements were performed using standard BET techniques. CPS guidelines are known in the art. See Lori T. Boock, Thomas F. Petti and John A. Rudesill, ACS Symposium Series , 634, 1996, pp. 171-183. These results are also reported in Table 3 below. CPS refers to cyclic propylene vapor treatment.

In general, in a catalyst containing conventional zeolite USY, the replacement of the rare earth with cerium does not exhibit a preferred zeolite surface area maintenance as compared to the addition of cerium to a catalyst containing clay-derived zeolite. Therefore, the advantages of the present invention are considered to be unpredictable.

Example 4. All four deactivation catalysts of Example 3 were then passed through an Advanced Cracking Evaluation (ACE) unit. Deactivated samples were evaluated in Kayser Technology's ACE Model AP fluid bed microactivity unit. See also U.S. Patent No. 6,069,012. The reactor temperature was 527 °C. The results of the study are presented in Table 4 below.

Compared to yttrium stabilized zeolites, from conventional zeolites (catalyst 1) to clay-based zeolites (catalyst 2), the catalytic activity is significantly reduced (in the case of a catalyst to oil ratio of 4, conversion) The absolute value of the rate is reduced by 4.4% by weight). In addition, coke has also increased. This means that clay-based zeolites are inherently less stable and less selective than conventional zeolites. Conversely, from conventional zeolites (catalyst 3) to clay-based zeolites (catalyst 4), there is no reduction in activity or increase in coke. Therefore, the addition of cerium compounds can improve the original stability and selectivity of clay-based zeolites. This is an unpredictable discovery.

Of Example 5 using the following criteria will be steam deactivated catalyst samples 2 and 4 further deactivation.

Criteria: The temperature was changed to 760 ° C (1400 ° F), 788 ° C (1450 ° F) and 816 ° C (1500 ° F), respectively, with 100% steam for 4 hours.

The surface area of the deactivated sample was then measured by the BET method and the zeolite maintenance rate for each catalyst and deactivation criterion was calculated. The results are shown in Table 5 below. As can be seen from the table, the catalyst 4 maintains a higher zeolite surface area than the corresponding catalyst containing lanthanum and lanthanides.

Claims (20)

A method of producing a catalyst comprising (a) treating a clay with a ceria source under alkaline conditions to produce a zeolite, and (b) combining the zeolite with a ruthenium compound, wherein the lanthanide is yttrium oxide (Y ₂ O ₃ ) The amount measured in the combination is from 0.5% by weight to 15% by weight based on the weight of the zeolite. The method of claim 1, wherein the clay is kaolin or a characteristic phase change of one or more kaolin clays. The method of claim 1, wherein the alkaline condition comprises contacting the clay with a compound selected from the group consisting of alkali metal hydroxides, silicates, aluminates, and mixtures thereof. The method of claim 1, wherein the source of cerium oxide is selected from the group consisting of tannin extract, colloidal cerium oxide, precipitated cerium oxide, rice husk ash, sodium citrate, and/or mixtures thereof. The method of claim 1, further comprising adding the seed crystal to the clay and the ceria source. The method of claim 1, wherein the zeolite produced in (a) comprises at least one metal impurity. The method of claim 6, wherein the metal impurity comprises a compound derived from a metal selected from the group consisting of iron, titanium, magnesium, calcium, and a mixture of two or more thereof. The method of claim 1, wherein the zeolite and the ruthenium compound are combined in (b) with the precursor of the matrix, and the method further comprises forming particle. The method of claim 8, wherein the zeolite produced in (a) is crystalline and has an average particle diameter in the range of 0.05 to 10 μm. The method of claim 8, wherein the average particle diameter of the particles is in the range of 20 to 150 μm. The method of claim 1, wherein the hydrazine compound is a water-soluble cerium salt. The method of claim 1, wherein the cerium compound is selected from the group consisting of cerium halide, cerium nitrate, cerium carbonate, and cerium sulfate. The method of claim 1, wherein the clay in (a) is in the form of microparticles having an average particle diameter in the range of 20 to 150 μm, and the zeolite is generated in situ within the clay microparticles. The method of claim 13, wherein the ruthenium compound is combined with the zeolite by impregnating the ruthenium into the granules. The method of claim 14, wherein the impregnation is carried out with an aqueous solution containing a cerium salt concentration of from 1 to 40% by weight, which is measured by cerium oxide. The method of claim 13, further comprising drying the zeolite microparticles after (b) combining with the hydrazine compound. The method of any one of claims 1 to 16, wherein the cerium compound contains a rare earth oxide in a weight ratio of 0.01 to 1 relative to the cerium oxide. The method of any one of claims 1 to 16, wherein the hydrazine compound consists essentially of a hydrazine compound or a hydrazine moiety. The method of claim 8, wherein the precursor of the matrix contains an inorganic oxide selected from the group consisting of cerium oxide, aluminum oxide, cerium oxide, and clay. The method of any one of claims 1 to 12, wherein the zeolite and the cerium compound are combined in (b) with the precursor of the binder.